MOF-coated mesh membranes separate oil from water

By Paul Grad | December 1, 2018

Current oil-water separation technologies, such as centrifugation, filtration, dissolved air flotation, distillation, oil skinners, adsorption and electrochemical methods, are of low efficiency and consume a lot of energy during complex separation processes. Mesh membranes have attracted much interest lately, and some polymers have been successfully applied onto mesh membranes. However, due to their oleophilic properties, the surfaces of those membranes are easily polluted or even blocked by oil.
Now, a ZIF-8-coated mesh membrane for high-efficiency oil-water separation has been prepared by a team from Jilin University (Changchun, China; www.jlu.edu.cn) and Sinopec Institute of Safety Engineering (Qingdao, China; www.sinopec.com). ZIFs — zeolite imidazole frameworks — are a subfamily of metal organic frameworks (MOFs) that exhibit various topologies and morphologies, and are chemically and thermally fairly stable.
The membranes have micro- and nano-scale architectures, and are fabricated by simply immersing mesh into a precursor solution at room temperature and atmospheric pressure. Water molecules are imbibed into a rough solid surface to form a barrier layer that produces a strong repulsive force to an oil droplet, which makes…